Windows Automatic Repair Loop
The computer boots to a blue "Preparing Automatic Repair" or "Diagnosing your PC" screen, appears to work on it, then either restarts back to the same screen or fails with a message that repair couldn't be completed.
Quick answer: An Automatic Repair loop means Windows has detected a startup problem and is trying to fix it, but the fix isn't taking — usually because of a corrupted system file, a bad update, or a failing drive underneath it. A couple of repair attempts is normal; if it keeps looping without change, it needs a different approach.
Likely causes
- A corrupted system file or boot configuration
- A Windows update that didn't install cleanly
- A failing hard drive or SSD that repair tools can't reliably read from
- A recent driver or software change that's interfering with startup
What you can safely check yourself
- Let it run through one full repair attempt without interrupting it
- If it offers "Advanced options," Startup Repair and System Restore (to a point before the problem started) are worth trying in that order
- Unplug any unnecessary USB devices before retrying, in case one is interfering
Avoid using "Reset this PC" options from this screen until you're sure what you'd lose — some reset modes remove installed programs and settings, and a small number remove personal files too. Check which option you're choosing carefully.
When it needs a proper look
If the loop continues after a couple of genuine repair attempts, or System Restore doesn't help, that usually means the underlying cause needs a proper look rather than more automatic attempts.